Air-brake system.



PATENTED JUNE 16, 1908..

nnrrnn snares earner ore-res,

HAROLD ROWNTREE, OF CHICAGO, ILLINOIS".

AIR-BRAIQE SYSTEM;

Specification of Letters Patent.

Patented June 16,1908.

Application filed March so, 1907. semi lie. 365,561.

self regulating system of operation of air brake, which is simple andeffipienta'nd at the same time positive and reliable and free from the many uncertainties inherent in present systems.-

A further object is to provide. a system of the nature referred to wherein the amount, of pressure applied to the brake will be dependent solely on the position of the engineers control handle.

A further objectpf the invention is to providean air brake system wherein the operation of the triple valve shall be such that the ati-ve arrangement of parts, all

brake pressure shall always vary in inverse relation to the train pipe pressure,

A further object is to provide means whereby the action of the triple valve and therefore the resulting brake pressure cannot be affected by leaks'in the triple valve, or by variations in'press'ure in the auxiliary tank.

i A further object of the invention is to pro: vide means whereby a variation in the auxiliary tank pressure is not an essential part of the system, and therefore the auxiliary tank can be made as large as desired, and so on able the maximum possible brake pressure to be but little below the original auxiliary tank pressure.

A further object is to provide an.equip ment of air brake mechanism whereby a car equipped therewith can be coupled upand operated with existin air brake systems, and, controlled by the ordinary form of engineers control valve.

. Other objects will appear more fully hereinafter.

The invention consists substantiallyin the.

construction, combination, location, and relas Will be more fully hereinafter .set forth, as shown in the accompanying drawing, and finally pointed out in the appended claims.

The single View of the drawing is'a diagram, parts .in section, an parts in elevation,

showing an alr brake system embodying the principles of my invention.

suitable,

An exhaust port P,

in connectionwith cars equipped the portion K, of the valve,

and while, for many reasons, I prefer to -em-- Themain tank-A, train pipe connections B, hose couplings G emergency valves D, auxiliary tank- E, an compressor F, may all be of the usual or any ordinary, well known, or convenient'construction or arrangernent, and in the detailsof construction thereof formno part of my present invention. g

The triple vall'le casingnis designated by reference sign G, and in t 's casing operates the valve, which is provided with a portion H of reduced diameter arranged to operate in a reduced extension or portion J, of the casing. Into this extension delivers a train pipe connection B. The reduced ortion H, of the valve is connected'with the arger portion K, throughthe-intermediate, stem L, thereby leaving opposed piston faces a and b, of diiiering areas on the portions li, and H, respectively ofnthe valve. nection M, delivers from the auxiliary tank E, to the triple valve casing extension J, and an auxiliary train pipe connection B, also delivers to said extension. A valveN is arranged in the connection of the train pipe B to the auxiliary tank, and, similarly, a valve O,-- is arranged pipe connection B, ranged to seat towards the train ipe.; portion H, of the valve controls t e connection of pipes M, and B, to the valve casing.

is provided in the triple valve casing, and is controlled by the portion K,of the valve. A connection R, extends from the valve casing to the brake cylinder S.

From the fore oing description it will be seen that the tripde valve is moved in one direction by the train pipe pressure, admitted toextension J, of the casing, through train pipe connection B, operating against the piston face 0. valve in the direction of the impclling force of the train pipe pressure, thus applied, may be opposed in any suitable or c nvenient manner. I have shown a most simple andv efficient arrangement wherein a spring T, is interposed'between the casing tnd the end of as clearly shown,

plo a spring having thopur )ose, function,

and arrangement described, Qftlo not desire to be limited or restricted in this respect.

With the c'onstruiitien and arrangement above described it will be readily seen that.

the movements of the triple valve are not de- The movement of the triple.

The pipe con- The a pendent upon variations in the auxiliary tank pressure, and are influenced solely by be illustrated by variations in'the train=p1pe pressure, and the variations in the brake c linder pressure acting on the faces, a, and

The operation of the triple valve can best ispecific examples. Suppose, for instance, e area of the larger piston of the valve 1s 8 square inches and that of tion occupied under normal running condiing, that is, with the auxiliary which is lower than the amount required to .m piston areas,

tions. Now, under these conditions a pressure of 7 0 pounds upon the smaller piston of the valve, that is, a train pipe pressure of 70 pounds, will give a total pressure of 6 X 70 or 420 pounds on the valve, and so hold'the said valve in the position shown in the drawand train pipe pressure cut off from the bra e cylinder, and said cylinder open to the exhaust. pose the train pipe pressure should be lowered to, say, 6 pounds; then the pressure on the valve piston is 6X 60, or 360 pounds,

hold the same in lap position, as in the ex ample above given, and hence the valve will begin to .move under the influence of the spring T, or other medium, 0 posing the train pipe pressure thereon, an thus close the brake cylinder exhaust port, and open the auxiliary tank connection to the brake cylinder through the space between the pistons H, and K, and hence the brake will be applied. The brake cylinder pressure is thus imposed upon the differing piston areas a, and 7), and therefore, as soon as thebrake cylinder pressure reaches, say, 15 pounds, the following equation is established 15 X (8 6) plus X 6 equals 390, and hence, since this is the pressure required, in the example taken, to maintain the triple valve closed, or in lap position, the valve will automatically move into such lap position as soon as the brake cylinder pressure attains fifteen pounds. Similarly, sup ose thetrain pipe pressure should be CHJJSGL to fall to 50 pounds then, A multiplied by the d illierence plus 50x6, e uals 390 only when A which represents the rake cylinder pressure, equals 45 pounds. In other words in this instance as soon as the brake cylinder pressure equals 45 pounds the valve again closes when the train pipe pressure is fifty pounds. In the same way it may be shown that when the train pipe pressure falls to 40 pounds, the brake cylinder pressure will reach pounds, provided the auxiliary tank 18 ofsullicicnt s1ze and contains sulhci'ent pressure to produce that pressure 111 the brake cylinder. With the train pipe pres- Now sup sure at 40 pounds and the brake cylinder at 75 pounds, an incl ease in the train pipe pressure to say 50 pounds, results automatically in -a reduction in the brake 'cylind er pressure to 45 pounds, the triple valve automatically operating under these conditions to produce such result and so on with other variations.

So, too, in case the air should leak in or out of thetriple'valve casing, or through the valve, or otherwise, the valve will move slightly toexhaust or pressure position, as the case may be, and so adjust itself to balance the leak, thereby keeping the brake cylinder pressure constant regardless of leaks. From the fore oing descr ption it follows that the brake cy inder pressure varies automatically in inverse ratio as the train pipe pressure varies, and regardless of anyleaks in any part of the triple valve, or of variations in the auxiliary tank pressure.

By providin the train pine connection B, to the triple va ve, independently of the auxiliary tank, and which connection is opened to the brake cylinder at the same time with the auxiliary tank, I secure the advantage, in long trains, of quickly reducing the train pipe pressure, throughout the length of the train, by admitting a portion of such pressure to the brake cylinder of each car, thereby making the application of the brakes more nearly simultaneous throughout the train. This however, does not result in effecting the total braking pressure exerted by the brakes,

.nor is it essential to 'the o eration of the system, but it secures the a vantage noted and hence is a desirablefeature in the system.

It is obvious that auxiliary. tank pressure might be used in place of the s ring T, to perform the same function, butll prefer to use I the spring as variations in the auxiliary tank pressure cannot be entirely avoided and hence, if auxiliary tank ressure were used, variations therein woult result in causing the brake pressure to vary somewhat from truly inverse proportion to the train pipe pressure.v If, however, the auxiliary tank should be made sulliciently large, variations in the pressure therein could be so reduced as to be practically negligible in practice. My invention, therefore, in its broadest scope is not to be limited to the particular form of opposing medium in the situation referred to, the essential feature being that the action of the'triple valve isdue to the combined elleet of the train pipe pressure and the brake pressure, a lessening 01 one necessarily mean- .ing a corresponding increase of the other before equilibrium can again be established.

The brake applying apparatus employed in connection withthe system maybe of any suitable or convenient construction, and, so far the breadth and scope of my present invention, sought-to be secured herein, is concerned, and'the specific construction of such apparatus is not of consequence so long as Q is of such construction and arrangement as toaccom lish the application of the braking effort ant in accordance with the relation and cooperative operation of the tri 1e valve as above described, and whereby tie brake cylinder pressure is inversely proportional to the train pipe pressure. In the particular form shown, to which, however, my invention is not to be 1, is arranged to operate in the cylinder S, to the stem 2, of which, is pivotally connected a lever 3, at a point intermediate its ends, as at 4. Near one end of lever 3, is connected a strong spring 5, the tension of which is normally exerted upon the lever 3, to rock the same about its pivot 4. To the other end of lever 3, as at 1,0 is connected a rack bar 6, with which cooperates a pinion 7, connected to the hub of a cam, whereby when the bar 6, is moved the cam 8 is rotated. The cam bears against one end of a lever 9. To the other end of the lever 9, is connected as at 11 arod 12, the other end of said rod being connected, as at 13, to the end of lever 3. A link 14, connects the lever 9 to the brake le-. ver 15, to which the brake rod 16, is connected in the usual manner. is also connected by rod 17, to a cooperating brake rod 19, in the usual manner.

Theoperation of the brake mechanism is as follows: When pressure is admitted to the brake cylinder S, by the operation of the triple valve, as above explained, the first effeet, the spring 5, being under sufiicient tension, is to rock said lever3, about its pivot 4, the point 13'becoming the fulcrum, and in a direction to shift the rod 6 towards the right thereby causing the pinion 7 to be rotated, and hence rotating the cam 8. By the bearing of the cam surface against the end of lever 9, said lever is rocked about the point 11,

as a fulcrum, thereby drawing on the link 14, I

and hence through the'cqualizing levers 15, 1'8, connecting rod 17, and brake rods 16 and '19, effecting a preliminary application of the brakes, sufficientto take up lost motion of the arts and to compensate for any wear on the raking surface of the shoes. When the braking pressure thus applied is sufficient to overcome thetension of the s ring 5, the fulcrurn of'lever 3, is transferre from the point 13, to the point 10, and thereafter, through the 'rod 12, the lever 9 is rocked about the point of bearing contact of the end thereof against thecam surface 8. The link 14, is connected to the rod 9, at a point closely adjacent its point of bearin contact against the cam 8, and consequent y the a plication of the pull thereon exerted throng the rod 12 is through a long leverage, thereb; greatly increasing the braking effort of the brakes.

I do not claim herein except in its combinative and cooperative relation the particular construction and arrangement of braking mechanismas the same forms the subject limited or confined, a piston The brake lever 15,

matter of a separate application, but I have shown and described a particular construc tion in order to show the relation and coop erative arrangement of the triple valve and the engineers valve controlling mechanism employed in a complete operating brake system- -which forms the subject of my present invention.

In an air brake system embodying the principles of my invention, and in cooperation with the brake mechanism and triple valve above described, I employ an engineers control valve so'constructed and arranged as to control the brake applying'pressure by regulating the train pipe pressure, and hence the triple valve, such. control being in definite relation with reference to the position ofrthe control valve handle. In other words, I employ an engineers control valve in connection with the system forming thesubject matter of the present invention, wherein the various positions of the operating lever of the control valve bears definite relations to the degrees of pressure admitted to the brake cylinder. Many specifically different constructions of engineers control valve may be devised for accomplishing this result. While, therefore, I have shown, and will now describe, one construction for accomplishing the desired objects, my invention is not to be limited or restricted thereto. In this articularv form shown the operation of the valve is controlled by the joint and cooperative action of an operating lever and the train pipe pressure the latter being opposed in a suitable manner.

Reference sign 20 designates the control valve casing having'the cylinders 21, 22, in the former of which operates a close fitting piston 23, said cylinder being opened to the atmosphere as at 24. A rock lever 25, piv otally mounted between its ends, as at 26,

has one end thereof connectedthrough a link 27, to piston 23, and the other end connected through the pivoted links 28, 29, to one end 32, of a lever pivotally mounted as at 31, the other end 33, of said lever serving as an operating handle. The valve 3a, is connected by a rod 35, to the link 28, said valve controlling the pressure supply and exhaust ports 36 and 37 At the point 38, of connection of the lever 25, to the link 27, the other end of which ton 39, operating loosely in the cylinder 22, and behind which is a spring 40, or other suitably arranged pressure medium. In practice I prefer to arrange the cylinders 21, and 22 in substantially right angular relation with respect to each other, It will be observed that the train pipe pressure is always imposed upon the piston 23, tending to move the sameto the limit of its stroke-in the cylinder 21, while such, pressure equalizes on opposite sides of the piston 39. It will also be seen thatas'long as the train is connected a link 30, is connected to a pisaga nst the increased strength of the spring 40, will strike a balance. The lever 25, therefore, W1ll automatically take a definite position for. every variation in pressure.

When the iston 23, is held at thelimit of its stroke the ever 25, is consequently held in a certain fixed position, enabling the link 28 to be rocked or swung about its point of pivoted connection with said lever 25, whenever the valve control handle 33 is operated to move 'the valve 34. When, however, the train pipe pressure falls below that of the opposing tion to close the ports which it controls.

medium, in this instance the spring 40, then,

under the influence of said opposing ressure acting through the links 27, and 30, t e point 38, is shifted towards the left, and in a definite relationto the degree of fall of the train pipe ressure, thereby shifting the lever 25, and hence varying the fulcrum of link 28, thereby automatically moving the valve in a dire[cother words, if the o crating handle 33, is

tion to close the exhaust port, and this 'resmoved so as to open t e exhaust port 37, the reduction in the pressure tends to cause such relative movement of. the pistons 23 and 32; as to cause the valve to move back into positoration of the valve to osed positioni oc-. curs whenever the pressure has attainedthe desired degree represented by the positioh of the control handle. Similarly,if the cofftrol handle has been moved to such position, as to open the supply ort, the increase of the train pipe pressure t us imposed upon the piston 23, causes such a shifting of the lever 25, as to cause the valve to automatically close the supply port.- Thus it will be seen that the ressure in the train pipt; will at all times be ffept automatically in'a delthite relation' and proportion with reference to the osition of the control handle. It will also "e seen that if the train pipe pressure would vary by leakage of air into the system through the supply port, or out through the exhaust port, or through defective or worn joints or valves, or otherwise, the engineers control valve will automatically move just enough one way or the other to reestablish the desired pressure indicated by the position of the control handle, thereby insuring a brake cylinder pressure corresponding accurately with the position of. the engineers con trol handle,'in direct action systems, while in indirect or exhaust systems it insures that the variation in the train pi'e pressure corresponds accuratel withteposition of the engineers control handle.

While I have shown a spring arranged to soopso 7'0 ries and .therefore would not give the uni- I form resultswhich are desirable to'secure.

- I do not claim herein the specific construction of engineers control valve shown and described as the same forms-the subject matter of a se arate application.

From thfe foregoing description it will be seen that I provide an exceedin ly simple and eflicient air brake system wherein the position of the en ineers control handle determines absolute y the pressure supplied to the brake cylinders.

It will-also be seen that leaky valves or train pipes will not affect the operation of the brakes, and therefore the brakes cannot creep on.

It will also be seen that since the operation of the tri le valve is not dependent on variations in t e pressure of the air in theauxiliary tank, said tank can be made as large as desired in proportion to, thesize of the brake cylinder, and consequently the reduction of the auxiliary tank pressure due to the expan sion when air is admitted to the brake cylinder can b'e'made'as low as desired, and the corresponding possible brake pressure c'an'be made practical y as high as the original tank pressure. I

It will also be seen that cars equipped with brake and triple valve mechanism embodying my inventions can be used in trains with cars equi ped with the systems at present in use, and t at an engineers control valve embodying the principles of my invention, or an engme or a motor car equipped therewith, 5

,bod ping the principles of my invention I se-- cure,a reat economy'in the consumption of air, an that the brake mechanism becomes operative instantly the train pipe pressure isreduced whether by the operation of the engineers control valve, the operation of'the emergency valves or the breaking of the 15 coupling between cars, as in the systems at present in use. I

Having now set forth the objects and na ture of my invention and'a construction embodying the principles thereof, and having explained such construction its purposes function and mode of operation, what I claim as new and useful, and of my own invention,

and desire to secure by Letters Patent is 1.. In an air brake system, a triple. valve casing having train pipe, auxiliary reservoir,

brakecylinder and exhaust orts, a valve arranged in said casing and a apted to control said auxiliary reservoir, brake cylinder and exhaust ports and means for controlling the train pipe operation of said valve through the conjoint action of the train pipe pressure and a differentially applied brake cylinder pressure.

2. In an air brake system, a triple valve casing having train pipe, auxiliary reservoir, 1 ke cylinder and exhaust orts, a valve arr n'ged in said casing and a apted to control said auxiliary reservoir, brake cylinder and exhaust'ports, means for subjecting the same to the train pipe pressure, and means for augmenting the action of the train pi e pressure With a differentially applied bra e cylinder pressure.

3. In an air brake system, a triple valve casing having train pipe, auxiliary reservoir, brake cylinder and exhaust ports, a valve arranged in said casing and adapted to control said auxiliary reservoir, brake cylinder and exhaust ports, and means for controlling the oprationof said valve through the conjoint action of the train pipe pressure, an. opposing spring and a differentially applied brake cyl inder pressure.

4. In an air brake system, a triple valve casing, a piston valve arranged therein and having differential areas, auxiliary reservoir, brake cylinder and exhaust connections controlled by said piston valve, a train pipe connection delivering to one end of said piston valve, a spring opposing the train pipe pressure, the auxiliary reservoir pressure adapted to be delivered to said differential areas.

5. In an air brake system, a triple valve casing, train pipe, auxiliary tank, and brake cylinder connections thereto, a piston valve for controlling both the cylinder and tank connections, to the casing, the train ipe pressure being applied directly to said va ve, a spring arranger to exert its tension upon said valve in opposition to the train pipe ,pressure, and means for augmenting the action of the train )ipe ressure by a difi'erentially applied bralre cy inder pressure.

6. In an air brake system, a triple valve casing, auxiliary tank, and brake cylinder connections thereto, a valve, an auxiliary train pipe connection to said casing, and

means for subjecting the valve to variations in brake cylinder pressure.

7 In an air brake system, a triple valve casing and valve, auxiliary tank, brake cylinder and exhaust connections to said casing and arrangedto be controlled by said valve, a train pipe connection to said casing whereby said valve is subjected to variations in the pressure, means for also subjecting said va ve to variations in brake cylinder pressure, independent means for opposingsaid pressures, and an auxiliary train pipe connection to said casing trolled by said valve.

8.- In an air brake system, a triple valve comprising connected pistons of different areas, a train pipe connectiondelivering to the face of one of said pistons, a spring-20p- 'sures whereby said arranged to be con- 7 mediate said pistons! 9. In an air brake system, a triple valve having connected pistons of difierent areas,

a train pipe connection of one of said pistons, a spring operating against the remote fa cc of the other of said pistons and in opposition to the train pipe ressure, and auxiliary tank, brake cylinder and exhaust port connections controlled by said valve.

10. In an air brake system, a triple valve constantly open to the action of the train pipe pressure, means for imposing a difierential brake cylinder pressure upon said valve tending to move the same in the same direction as the train pipe pressure, a spring arranged to oppose the action of such presdelivering to the face matically under varying conditions of train pipe pressure, auxiliary tank, brake cylinder and exhaust connections controlled by said valve, and arranged in such relation as to automatically maintain uniform pressure in the brake cylinder regardless of variations in the auxiliary tank pressure, or leakage.

11. In an air brake system, the combination of air brake cylinders, a triple valve and train. pipe pressure controlling mechanism, of means for maintaining a braking pressure in inverse proportion to the train pipe pressure, regardless of leakage of pressure at any point in the system.

12. In an air brake system, a brake mechanism, a controlling mechanism and an auxiliary tank, in combination With a triple valve casing in said cylinders, said pistons being connected together, one of said pistons controlling the auxiliary tank connection, and the other controlling the brake mechanism and exhaust connections, delivering to the reduced cy 'nder, and a spring arranged in the enlarged cylinder to oppose the train pi e pressure.

13. In an air bra e system, a

valve is operated auto having an enlarged and a reduced cylinder, pistons respectively working brake inecha train pi e connection anism, and a controlling mechanism having a handle in combination With means inter mediate said mechanisms for maintaining the pressure in the brake cylinder in constant relation to the osition of the control handle regardless of s ight variations in the main tank pressure and regardless of slight leakage at any oint in the system. i

14. In an air rakesystem, a triple valve, means for moving said valve into osition to admit pressure to the brake cylin means foropposing said valve moving means with a differential brake cylinder pressure.

15. In an air brake system,.a tri 'le valve, means for moving said valve to tlinit pressure to the brake cylinder,-and; ineans for 35 sure.

opposing said valve moving means with the conjoint action of the train ipe prlessure and a differentially applied bralie/cylinlder pressure. 5 16. In an air brake mechanism, a triple valve comprising connected pistons of difierent areas, and connections when by the brake cylinder pressure is imposed on both piston areas.

17. In an air brake system, a triple valve comprising connected pistons of different areas, means for supplying train p1 e pressure against one of said pistons an means for su plying brake cylinder pressureto the space etween said nstons.

. 18. In an air bra e system, a triple valve comprising connected pistons of difierent areas a brake cylinder connection to the space between sald pistons, and a train pipe connection delivering to one end of said pistons 19. In an air brake system, a triple valve comprising connected pistons of (lifl'erent areas, a brake cylinderconnection to the space between said pistons, a train pipe connection delivering to one end of one of said pistons, and a. ,pre ssure medium imposed upon the opposite end of the other of said pistons.

20. In an air brake system, a triple valve and means for automatically adjusting said alve to compensate for leakage at any point in. the system, whereby the brake cylinder pressure is maintained in inverse proporional relation to a definite train pipe pres- 21.-, In an air-brake system, a brake mechanism, a controlling mechanism for the'train pipe pressure, including an operating handle adapted be set to various'po'sitions auto- 40 matic mea s for establishing correspondingly varying con itions in the train pipe pressure, a triple 'valvesubjected to the varying conditions of train pipe pressure and having differential areas, means for opposing the train pipe pressure and an auxiliary tank connection to the brake mechanism arranged to be controlled by said valve and delivering to the differential areas of said. valve.

22. In an air brake system, a brake incohanism, a triple valve for controlling the sup ply of pressure thereto, and meanswhereby the pressure maintained in the brake cylinder through the operation of the triple valve .is not effected by the movements of the valve due to leakage at any point in the system.

23. In an air brake system, a brake mechanism, a triple valve for controlling the supply of pressure thereto, and means whereby said valve automatically adjusts itself to compensate for leakage at any point therein.

24. In an air brake system, a brake mechanism, a train pipe and means for maintaining pressure in the brake mechanism in inverse proportion to the train pipe pressure within the limits of the sources such pressures. A

v 25. In an air brake system, a brake mechof supply of anism, a controlling mechanism for the train pipe pressure including an operating handle: adapted to be set to various positions, auton1\ tic means for establishing correspondingly varying conditions in the train pipe pressure,

.a ti iple valve subjected to the varying conditions of train pipe pressure said valve having differential areas, a spring arranged to act upon said valve in opposition to the train pipe pressure, and an auxiliary tank connec tion to the brake mechanism arranged to be controlled by said valve; and delivering to the differential areas of said valve.

26. In an air brake system, a triple valve and means for automatically moving the same to maintain inverse proportional relation between the brake cylinder and train pipe pressures Within the limits of the pressures of the sources of supply, and regardless of leakage at any point in the system.

27. In an air brake system, a brake cylinder, a pressure controlling mechanism including an operating handle, and automatically operatin means for maintaining a constant relation etween the pressure in the brake cylinder and the position of the control hand controlling mechanism mcl'uding'an operat-- ing handle, in combination with means for maintaining a definite and uniform pressure in the brake cylinder for each osition of the operatin handle, Within the 'mits of pressure of t e sources of supply thereof, and regardless of slight leakage at any point in the I system.

30. In an air brake system, a brake cylinder, a train pipe, and a train ipe pressure controlling mechanism, in com ination with means whereby, under normal conditions. the pressure in the brake cylinder is varied solely by varying the position of the control handle.

In testimony whereof I- have hereunto set my hand in the presence of the subscribing Witnesses, on this 28th day of March A. D., a

HAROLD ROWNTREE.

lVitncsses: v

JosEPn KLEIN,

S. E. DARBY. 

